Mrs Griffith lost her husband, mother and two foster sons in the tragedy.

Dyche was found not guilty of death by dangerous driving.

Liam Govier, 14, died when the car plunged into Llyn Clywedog, near Llanidloes

It has also been revealed at Caernarfon Crown Court that Dyche had previous convictions for driving offences.

When the incident happened in April 2011 he had just finished a driving ban for driving while disqualified and without insurance in January that year.

He had previously been disqualified for driving without insurance and while disqualified in August 2010.

Dyche had also been convicted of theft the same year.

During the trial, Mrs Griffith, 56, told how the family had been on holiday and returning from a day trip when the incident happened.

She went to pull into a lay-by near Llyn Clywedog and it was at that moment she felt her Peugeot 807 people carrier being shunted from behind.

Denise Griffith, left, survived, but she lost her mother Phyllis Hooper (right), husband and two foster sons

"The next thing I knew we were going anti-clockwise," she told the court. "I saw the rocks, and sky and rocks again, and the water just hit my face.

'It's my fault'

"I couldn't undo my seat belt at first. I sat in the seat thinking 'how long have I got to live'."

Mrs Griffith and the family dog, Milly, eventually escaped from the car but she said she knew her family "had not made it".

She lost her husband Emyr, 66, her mother Phyllis Hooper, 84, and Peter Briscome and Liam Govier, both 14 and who had autism.

Police sealed off the scene following the incident in April 2011

The court heard that shortly after the incident, Dyche, a married father, told a paramedic: "I shouldn't have done it. I was late for work. It's my fault."

He also told a police officer: "It's my fault."

Witnesses told jurors they had seen Dyche overtake and then clip Mrs Griffith's car.

The court heard how Dyche left home for work in a Ford Mondeo shortly after 14:00 BST on the afternoon of the crash.

He was driving eight miles to Llanidloes to start work at 14:30 BST.

He said he came up behind two cars - a VW Passat car and the people carrier, being driven by Mrs Griffith, ahead of it.

They were travelling at about 40mph and he followed them for about a mile.

He said he began to overtake the VW but saw the Peugeot 807 start to turn right across his path towards a lay-by and he struck the vehicle.

Mrs Griffith told the court: "I know my life has been ruined. It's the most lonely, lonely place to be."

Reacting to Dyche's convictcion, she said: "This has been the worst time of my life, and while my faith has helped me over the past year and a half, no words can express how much I miss my family and how much my life has changed since that day in April 2011.

"Whatever the outcome from today would have been, it would not have changed anything.

"I would like to take this opportunity to thank all the emergency service personnel who helped that day, Also my family and friends.

"Also Mrs Rowlands who was kind enough to look after my dog Milly. I've not been able to thank her myself.

"All I ask now is that the media respect my privacy and allow me to grieve for my family in peace."

The birth mother of Liam Govier welcomed Dyche's sentence.

Alison Govier, 38, said she was "devastated" by her son's death, calling him "a lovely bubbly boy, a lovely smiley little chap".